The revelation has sparked widespread speculation and criticism that the New York billionaire is making false claims to appeal to voters and raises ethical concerns that he could award himself a last-minute return on the loan.

“From a public interest point of view, the public deserves to know who’s funding our candidate so they can make informed judgment about who to support based on that information,” said MapLight President and Co-Founder Daniel Newman. “This is a big problem for the public because we are all in the dark about who is ultimately going to be paying back Mr. Trump’s loans.”

It’s unlikely Trump will raise $17.5 million or more before Election Day. After all, FEC law states that individual donors can only give up to $5,400 in donations per election, which breaks down to $2,700 in the primary election and $2,700 in the general election. Political action committees are capped at $5,000 per election.

According to Open Secrets, the Trump campaign committee’s individual contributions total a modest $7.5 million, or just 30 percent of total funds.

Pushing those dollars closer to the total debt sum would require a lot of legwork from the Trump campaign. Unless the real estate mogul breaks mold and backs up the red donate button on his website with actual fundraising events, it seems far-fetched donors could cover all his debts.

Direct reimbursement from the Republican Party is also unlikely, since donations from the party top out at $5,000 per election.

However, there could be an emergency option to help the party skirt that legal limit. It's called a coordinated party expenditure, and it lets the Republican National Committee donate up to $23.8 million to its presidential nominee.

It’s possible that money could go to Trump, but the RNC hasn’t returned NBC Bay Area’s requests for comment.